<template>
  <el-color-picker v-model="theme" class="theme-picker" :predefine="predefineColors"  popper-class="theme-picker-dropdown">
  </el-color-picker>
</template>
 
<script>
const version = require("element-ui/package.json").version; // 版本号
const ORIGINAL_THEME = "#409EFF";
 
export default {
  name: "colorPicker",
  data() {
    return {
      chalk: "",
      theme:ORIGINAL_THEME,
      predefineColors: [
        "#409EFF",
        "#ff4500",
        "#ff8c00",
        "#ffd700",
        "#90ee90",
        "#00ced1",
        "#1e90ff",
        "#c71585",
        "rgba(255, 69, 0, 0.68)",
        "rgb(255, 120, 0)",
        "hsv(51, 100, 98)",
        "hsva(120, 40, 94, 0.5)",
        "hsl(181, 100%, 37%)",
        "hsla(209, 100%, 56%, 0.73)",
        "#c7158577"
      ]
    };
  },
  mounted(){
    // if(this.CheckIsColor(localStorage.getItem('UserThemeColor'))){
    //   this.theme=localStorage.getItem('UserThemeColor')
    // }
    this.theme='#6689f1'
  },
  watch: {
    theme(val, oldVal) {
      if (typeof val !== "string") return;
      if(localStorage.UserThemeColor!=val){
        localStorage.setItem('UserThemeColor',val)
        location.reload()
      }
      const themeCluster = this.getThemeCluster(val.replace("#", ""));
      const originalCluster = this.getThemeCluster(oldVal.toString().replace("#", ""));
      
      const getHandler = (variable, id) => {
        return () => {
          const originalCluster = this.getThemeCluster(
            ORIGINAL_THEME.replace("#", "")
          );
          const newStyle = this.updateStyle(
            this[variable],
            originalCluster,
            themeCluster
          );
 
          let styleTag = document.getElementById(id);
          if (!styleTag) {
            styleTag = document.createElement("style");
            styleTag.setAttribute("id", id);
            document.head.appendChild(styleTag);
          }
          styleTag.innerText = newStyle;
        };
      };
 
      const chalkHandler = getHandler("chalk", "chalk-style");
 
      if (!this.chalk) {
        const url = `https://unpkg.com/element-ui@${version}/lib/theme-chalk/index.css`;
        this.getCSSString(url, chalkHandler, "chalk");
      } else {
        chalkHandler();
      }
 
      const styles = [].slice
        .call(document.querySelectorAll("style"))
        .filter(style => {
          const text = style.innerText;
          return (
            new RegExp(oldVal, "i").test(text) && !/Chalk Variables/.test(text)
          );
        });
      styles.forEach(style => {
        const { innerText } = style;
        if (typeof innerText !== "string") return;
        style.innerText = this.updateStyle(
          innerText,
          originalCluster,
          themeCluster
        );
      });
 
    }
  },
 
  methods: {
    CheckIsColor(bgVal) { 
　　var type = "^#[0-9a-fA-F]{6}$"; 
　　var re = new RegExp(type); 
　　if (bgVal && bgVal.match(re) == null) { 
　　　　type = "^[rR][gG][Bb][\(]([\\s]*(2[0-4][0-9]|25[0-5]|[01]?[0-9][0-9]?)[\\s]*,){2}[\\s]*(2[0-4]\\d|25[0-5]|[01]?\\d\\d?)[\\s]*[\)]{1}$"; 
　　　　re = new RegExp(type); 
　　　　if (bgVal.match(re) == null) { 
　　　　　　return false;
　　　　} else { 
　　　　　　return true;
　　　　} 
　　　} else { 
　　　　return true;
　　} 
},
    updateStyle(style, oldCluster, newCluster) {
      let newStyle = style;
      oldCluster.forEach((color, index) => {
        newStyle = newStyle.replace(new RegExp(color, "ig"), newCluster[index]);
      });
      return newStyle;
    },
 
    getCSSString(url, callback, variable) {
      const xhr = new XMLHttpRequest();
      xhr.onreadystatechange = () => {
        if (xhr.readyState === 4 && xhr.status === 200) {
          this[variable] = xhr.responseText.replace(/@font-face{[^}]+}/, "");
          callback();
        }
      };
      xhr.open("GET", url);
      xhr.send();
    },
 
    getThemeCluster(theme) {
      const tintColor = (color, tint) => {
        let red = parseInt(color.slice(0, 2), 16);
        let green = parseInt(color.slice(2, 4), 16);
        let blue = parseInt(color.slice(4, 6), 16);
 
        if (tint === 0) {
          // when primary color is in its rgb space
          return [red, green, blue].join(",");
        } else {
          red += Math.round(tint * (255 - red));
          green += Math.round(tint * (255 - green));
          blue += Math.round(tint * (255 - blue));
 
          red = red.toString(16);
          green = green.toString(16);
          blue = blue.toString(16);
 
          return `#${red}${green}${blue}`;
        }
      };
 
      const shadeColor = (color, shade) => {
        let red = parseInt(color.slice(0, 2), 16);
        let green = parseInt(color.slice(2, 4), 16);
        let blue = parseInt(color.slice(4, 6), 16);
 
        red = Math.round((1 - shade) * red);
        green = Math.round((1 - shade) * green);
        blue = Math.round((1 - shade) * blue);
 
        red = red.toString(16);
        green = green.toString(16);
        blue = blue.toString(16);
 
        return `#${red}${green}${blue}`;
      };
 
      const clusters = [theme];
      for (let i = 0; i <= 9; i++) {
        clusters.push(tintColor(theme, Number((i / 10).toFixed(2))));
      }
      clusters.push(shadeColor(theme, 0.1));
      return clusters;
    }
  }
};
</script>
 
<style>

</style>